1. Field of the Invention
The present invention relates to user interfaces for computer systems. More particularly, the invention relates to audio cues to assist in manipulation of objects in a computer generated environment.
2. Background
Human-computer interactions have changed over the years from batch processing of punched cards, to on-line text-based interactions known as command line interfaces, to the current generation of graphical user interfaces such as are found in use with most desktop personal computers. As the computational capabilities of modern computers have increased so have the uses to which these computers have been applied.
These increases in computational power have led to a number of applications which require the manipulation of computer-generated objects in multi-dimensional environments. Some techniques have been developed to facilitate the placement of objects in two-dimensional (2D) spaces such as the ability to snap to a grid.
Computer applications incorporating three-dimensional (3D) graphics present substantial user-interface challenges due to the increased complexity of the space. Working with objects in 3D can be difficult because of the lack of spatial information afforded by the 3D environment. In the "real world," shadows, texture velocity, specular highlights, reflections, emmisive and reflective light sources, and other information are available to interpret into size, shape, and position. Even photorealistic renderings that are too compute intensive to render in real-time hardly compare to the richness of information provided to our visual senses in the real world.
Physiological factors also play a role in human perception. In the real world, humans rely on binocular vision to help judge depth, although its utility is limited to about 20 meters. A widened field of vision is really the main benefit from having two eyes for tasks such as driving.
Also important to human perception of distance is the information received from real or apparent motion. Motion parallax is the difference in motion across the visual field, for example, as seen out the side window while riding in a car. That is, things near you appear to whiz by, while the horizon seems motionless. Kinetic Depth Effect (KDE), is a related phenomenon that gives us shape information about an object when it, or the human viewer undulates. Human viewers tend to move back and forth, rather than holding heads and eyes in one position. When both human viewer and the viewed objects remain motionless (as in a virtual world), 3D objects may be perceived as flat. The primary problem with creating motion parallax and KDE in the virtual world is limited computer performance. In other words, animation must be imperceptibly smooth to be effective and not annoying. However, frame rates on widely distributed, current generation computer systems are not high enough to produce the proper effect.
Current 3D editors require the user to visually check the size and position of objects. In order to clearly ascertain the size and position of an object in a complex composition in 3D space (3-space), a user may need to switch between several camera angles and/or numeric display of X/Y/Z axial position and rotation. This approach is computationally intensive, tedious, slow, and error-prone.
There is a need for a mechanism for aurally comparing quantitative information.
Further, there is a need for tools to make computer users more effective in 3-space and to overcome the inherent limitations of the artificial 3D environment. Such tools as methods and apparatus for quickly and accurately moving and/or sizing objects in a computer representation of a composition in 3-space would make users of 3D computer applications more effective and efficient.